Shortness of breath

Dyspnoea is shortness of breath or “hunger for air”, and is most often seen in cardiac or respiratory disorders. And it is also commonly reported by people with ME/CFS – in fact, 80% of the 2073 consecutive patients in a Belgian study of 2001 reported dyspnoea after exertion, and because of this the symptom was later included in the Canadian Definition criteria for ME/CFS.

A study from Georgetown University, Washington published in the Global Journal of Health Science has some fascinating data on dyspnoea in ME/CFS patients. Overall, they found that 54% of 257 ME/CFS patients reported significant dyspnoea compared with 456 control people with similar sedentary lifestyles (3%). Also, the dyspnoea correlated with exertional exhaustion, low physical functioning, pain, severity of rapid heart rate, muscle spasms and dizziness. However, pulmonary function testing was normal overall in both groups, e.g. there was no asthma or obstructive pulmonary disease. What seemed to be different between patients and controls was the presentation of breathing problems – the patients reported more sensory complaints, such as dizziness and chest pain, following specific laboratory measurements requiring deep breaths in and out.

So, what does this mean? Well, apparently, the sensation of shortness of breath is a very complex process indeed. It involves nerve inputs to and from the brain, airway pressure sensors, respiratory muscles and a host of physiological mechanisms . The authors suggest that the reported breathing difficulties could well be the result of an increased ‘sensory hypersensitivity’, such as an imbalance between the elements of the nervous system sensing inspiration and those sensing when air intake has been sufficient.